This application claims the priority of German Patent Document 100 20 694.8, filed in Germany, Apr. 27, 2001, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a spinning machine having a plurality of spinning stations, each of which comprise a drafting unit and a stopping device for fiber material fed to the drafting unit, as well as devices movable along the spinning stations for monitoring end breaks and for activating the stopping device of a spinning station needing maintenance.
The spinning stations of a spinning machine have to be monitored for end breaks so that in the case of a spinning station needing maintenance, normal spinning operation can be resumed. Practical experience has shown that in the case of a plurality of spinning stations, it is not always necessary to monitor all spinning stations continuously. Rather more, intermittent scanning at set intervals is frequently permissible, whereby only a fraction of the cost is required for practically the same level of effectiveness.
A spinning machine of the above mentioned type having intermittent end break monitoring is prior art in German published patent application 44 12 670. The means for establishing an end break and for activating a stop device at a spinning station needing maintenance are arranged on one carriage, so that after an end break has been established, the fiber material being fed can be quickly stopped. Because the stop device is located on the one hand in the area of entry of the fiber material in the drafting unit, the thread monitored by the sensor however is located downstream of the drafting unit, the carriage is of relatively large dimensions, for which there is not always the necessary room available on the spinning machine.
It is known from the non-generic German published patent application 27 31 019 (corresponding U.S. Pat. No. 4,122,657) that a sensor for establishing an end break is arranged on a carriage, which is pulled along by a metal, electroconductive traction belt. The electric signals generated by the sensor are transmitted via the traction belt to a stationary plotting station.
It is an object of the present invention, to significantly simplify the spinning machine of the above mentioned type with regard to the above mentioned apparatus.
This object has been achieved in accordance with the present invention in that a first carriage with at least one sensor for monitoring an end break and a second carriage having an actuator for activating the stopping device of a spinning station needing maintenance are provided.
Because the above mentioned apparatus are divided over two carriages, each carriage can be traversely moved to that point where it can carry out its function best. The spatial distance between the stopping device at the drafting unit of a spinning station and the spun thread is no longer of importance. As each carriage only comprises those elements necessary for a particular function, they can be designed to be sufficiently small. Hereby, with regard to the latter mentioned prior art, an electric coupling of the two carriages presents no problems. A purely mechanical coupling in the headstock of the spinning machine is, however, a possible alternative.
Both carriages can, in an embodiment of the present invention, each be pulled backwards and forwards by means of suitable traction means along a running rail. It can be provided that each carriage is arranged at at least one drive motor of its own, located for example in the headstock of the spinning machine, which drive motor activates the traction means. In the case of a flexible traction means, a belt or a wire can be involved.
When, as is generally known, the traction means is electrocondutive, the end break signals can be transmitted via the traction means from the sensor of the first carriage to the actuator of the second carriage. In the case of such electric couplings, the spinning stations in need of maintenance are identified at first by electronic means and this information is subsequently transmitted further.
In the case of such an electric coupling it is purposeful to pull both carriages in the same direction through the machine, whereby the second carriage follows the first carriage at a short distance behind. Thus short time intervals can be observed between the establishing of an end break and the stopping of the fiber material feed at the relevant spinning station.
In the case of certain preferred embodiments of the present invention, a joint drive motor comprising an intermediate gear can be arranged at the traction means of both carriages. The drive motor and the intermediate gear can be located in the headstock of the spinning machine. What is involved here is a purely mechanical coupling without electronic means or electronic spinning station counters.
Also in the latter case, the second carriage can follow the first carriage at a constant distance, in that it, for example, travels behind at a distance of three quarters the distance between two spinning stations. In the latter case it is of course necessary that both carriages can travel beyond all the spinning stations at each machine end.
It is generally known from the latter mentioned prior art that, in the case of a ring spinning machine, the movements of the ring travellers are scanned. The individual ring travellers are moved namely by the thread to be wound up, so that always then, when such a movement of a ring traveller does not occur, it is assumed that an end break is the reason. By taking advantage of this fact, it can further be provided that the first carriage can be guided on a ring rail arranged at the spinning machine. Additionally a sensor for identifying a spinning station can be arranged to the sensor for detecting a broken thread, so that between two spinning stations, where there is no thread present, an end break is not indicated. The identification of a spinning station can, for example, take place via respective bore holes in the ring rail. Over each bore hole, a measuring window could then be opened by a sensor for identifying the ring traveller movements.
These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein: